The present invention relates to a device for monitoring the travel time of mail shipments which includes a motion sensor, a memory for compiling the measured values and an electronic evaluation unit.
It is customary to monitor the travel time of mail shipments by using so-called delay monitors which are dispatched together with the mail shipments to be transported and include devices with which the motion sequences of the mail shipments are recorded. The devices of this type employed in the past include a motion sensor which records motion during the entire transit time of the shipment. The forces generated during transport of the mail shipments act on the sensor and the values determined by the sensor are retained in the form of a motion-over-time diagram. If the shipment is at rest, that is, it is not being transported, the sensor does not record anything. With this method it is possible to determine, for example, whether a shipment has lain at complete rest for several days in an undue manner after being transported for several hours.
The motion-over-time diagram recorded by the delay monitor can be evaluated at a central location and a desired/actual value comparison makes it possible to localize possibly existing stops in delivery or dispatch since the normal transporting paths and transporting times are known.
The delay monitors employed in the past have the drawback that they have a thickness of about 3 cm and that they are configured as a rigid unit in the form of a small package.